Scientists have repeatedly warned about threats caused by increased sea level, which is a topic of new studies published in geophysical research letters. According to research, coastal cities throughout the continent sank at a rather fast pace, increasingly aggravating the risk of mass exodus and infrastructure damage in a relatively close time. Using satellite data, scientists studied the level of subsidence of 99 coastal cities on six continents and observed that the speed of these cities sank faster than the steps where sea level increased.
The concept of decreasing land is easy to understand: it occurs when the lower surface is moved or removed, causing the surface of the upper sink, either gradually or suddenly, as explained by USGS. The extraction of submission of water and mining activities is some of the main reasons behind the decline of the soil.
As part of the latest study, a team measured the subsidence that occurred in 99 of these cities between 2015 and 2020 and found that cities in Asia were at the highest risk. Fast land subsidence is also observed in coastal cities throughout Africa, Australia, Europe and North America. Tianjin, Semarang, and Jakarta recorded the worst sinking rate of only below 1.2 inches per year, which was 15 times higher than the level at which the global average sea level increased. PER reports of the BBC, Jakarta is the city that is the fastest immersed in the world. With a combined population of more than 59 million people, Chittagong in Bangladesh, Tianjin in China, Manila in the Philippines, and Karachi Pakistan is among the worst cities with the highest risk attached to them.
A one-two threat for coastal cities
One third of the cities observed as part of this study recorded a subsidence of more than 0.4 inches per year, which was sufficient stat about. In particular, a high subsidence has been observed in industrial and housing areas. The extraction of ground water which is not regulated is a recurring theme in almost all the city risk, requires an urgent government intervention with the right policy to avoid terrible consequences if the trend trend continues.
Whammy Double of sea level rise and the faster level of land subsidence only accelerates the risk of sinking land that is faster than what is predicted by the current climate change model. According to the data compiled by NOAA and sharing through Climate.gov, global sea level reaches a record high of 3.6-inches in 2020, and the level in which sea level increases only accelerated. According to the World Economic Forum, Dhaka, Lagos, and Nigeria can have a land area that sinks underwater by YEA 2100 if the sea level trends increase and the land subsidence continues.
Fortunately, not all lost. With the extraction of the controlled groundwater mandated by government regulations, cities such as Jakarta and Shanghai managed to slow down dramatically in which these cities were immersed. However, certain areas in cities closer to the sea still record a subsidence of 0.4 to 2 inches per year based on observation of vision lines (LOS).